Hydraulic turbo couplings



July 18, 1961 H. SINCLAIR 2,992,534

HYDRAULIC TURBO COUPLINGS Filed Nov. 27, 1956 M VE/VTOQ Hapold Sinclaz'zilnite This invention relates to hydraulic turbo couplings of the typecomprising vaned impeller and runner elements, one of the said elementsbeing rotatable together with a casing that extends over the back of theother element. The primary portion or impeller may be either the outervaned element, i.e., the element that rotates with the casing, in whichcase the secondary portion or runner is the inner element which islight, i.e., of relatively low inertia, or on the other hand theimpeller may the light inner elements in which case the runner is theouter element which together with the aforesaid casing is heavy, i.e.,has relatively high inertia.

The invention relates particularly but not exclusively to hydraulicturbo couplings of the aforesaid type wherein a scoop tube, that may befixed or adjustable, operates Within a casing that is rotatable with oneor other of the said vaned elements and is used to transfer liquid fromthe said casing, which may be the casing mentioned in the previousparagraph or may be an additional casing.

There are advantages in using the vaned element as sociated with thecasing as the impeller; notably when the turbo coupling is of the typethat can be used for reduced speed drive with the working circuit in thepartially empty condition and with correspondingly lower centrifugalpressure therein, which results in a slower rate of emptying throughleak-off nozzles or quick emptying valves mounted in the casing.

It is good practice, when using hydraulic turbo couplings in conjunctionwith internal combustion engines, to mount the heavy impeller and casingdirectly on the engine crankshaft, through the intermediary of adiaphragm plate, which connects the crankshaft flange to the impeller.The said diaphragm plate affords a torsionally stiff connection thatenables the high inertia of the impeller and casing to be accepted bythe engine manufacturer even when the impeller carries, in addition tothe above-mentioned casing that extends over the back of the runner, arotatable reservoir chamber that serves to receive working liquid fromthe working circuit of the coupling and in which there is disposed anadjustable scoop tube that returns working liquid from the reservoir tothe working circuit and serves as a means controlling the degree offilling of the working circuit. In turbo couplings of this type therunner is mounted on an output shaft carried by a pair of bearingsspaced apart and housed in the impeller hub and in the casing thatencloses the runner; hence, the axis of rotation of the impeller and therunner elements are coincidental.

With the upward trend in horse power and speed, and number of enginecylinders with increased length of engine crankshaft, the abovedescribed arrangement has been found unsuitable in some cases due to theweight of the impeller and the parts rotatable with it causing unduedeflection of the engine crankshaft, and consequently the impeller hasbeen provided with an extension shaft, supported in an outboard bearingthrough which shaft the engine is coupled to the impeller. This method,however, involved additional cost and increases the overall length ofthe installation, and usually introduces a more diflicult torsionalvibration problem due to the resilience of the extension shaft.

It is the practice in marine diesel engine applications tates Patent alot:

of the Vulcan gear wherein the hydraulic turbo coupling is incorporatedwithin the casing of the reduction gearing, to connect the primaryportion of the turbo coupling to the engine crankshaft by anintermediate shaft supported in a bearing in the gear case, and in manycases the primary portion or impeller must comprise the lighter innerelement for the reason that considerations of the permissible torsionalvibrations in the engine and impeller system do not permit the heavierelement to be driven by the said intermediate shaft.

The object of the present invention is to provide a hydraulic turbocoupling of the foregoing type, either with or without a scoop tube,which when used in association with an internal combustion engineovercomes the above-mentioned difficulties.

In accordance with the invention the primary member of a hydraulic turbocoupling which includes an impeller and a rotatable casing that extendsover the back of the secondary member or runner is provided with aspigot bearing for supporting part weight of the secondary member forrotation Within the primary member, and a further bearing supportingpart weight of the primary member through a sleeve member that surroundsthe output shaft and is provided together with a fixed housing forsupporting the said further bearing, and a radial clearance is presentaround said output shaft within said sleeve member, said radialclearance being not less than 4 of the shaft diameter measured in theregion where the greatest clearance is required around said shaft topermit of the axes of rotation of the primary and secondary members tobe non-coincident.

In order that the invention may be clearly understood and readilycarried into effect it will now be described in more detail withreference to the accompanying drawing, the single figure of which is aview in longitudinal section of a turbo coupling embodying theinvention.

Referring to the drawing, the runner 1 is located adjacent the inputside of the coupling and the impeller 2 is located towards the outputside. The impeller 2 has connected to it a driving casing 3 that extendsover the back of the runner l and is provided with a central boss or hub4 (lower part of the figure) having a flange 5 to which the flange 6 ofa diesel engine crankshaft can be bolted, so that effectively the saidcrankshaft is rigidly connected to the impeller 2. The runner 1 isformed with a central boss 7 that is bolted to a flange 8 on an outputshaft 9, the inner end of shaft 9 being journalled in a spigot bearing10 within the boss 4 of the casing 3. The outer end of the output shaft9 is provided with a flange 11 for connection through a semi-flexiblecoupling, viz: one that permits of angular misalignment of the shafts tothe member 12 mounted on the driven shaft. The impeller 2 is formed witha central boss 13 which is rigidly bolted to a flange 14 on a sleevemember 15 that surrounds the output shaft 9, and the outer end of thesleeve member 15 is supported in a bearing 16 Within a scoop tubemanifold 17 mounted on a fixed bracket 17a, which is stationary butwhich may be adjusted in lateral position and in height to determine theposition of the bearing 16 relative to the engine seating.

The coupling is provided with a cylindrical reservoir 18 one end ofwhich is bolted to a flanged connection 19 on the radially outer part ofthe driving casing 3, and the other end of the reservoir 18 is formed byan end plate 20 with a large central orifice the inner periphery ofwhich runs with suitable clearance within the scoop tube manifold 17,the central part of the plate 2.0 and the manifold being shaped to formlabyrinths to prevent. the egress of liquid. The manifold 17 carries ascoop tube 21, with ascooping tip 21a, slidable in guides within ahousing 22, which scoop tube, as is well known in the art, trans-2,992,534. a a V f fers liquid from the rotating casing 18 through ducts(not shown) in the scoop housing 22 to an external cooler from which theliquid returns via ducts 2a to the working chamber formed between thevaned elements 1 and 2. The said scoop tube tip 21a is capable ofmovement towards and away from the periphery of the reservoir 18 bymeans of a control lever 23 carried by a control pin 24 that projectsthrough the manifold 17 and scoop housing 22 and is drivably coupled tothe scoop tube through the lever 24a.

The casing 3 is provided with spring loaded centrifugally operatedvalves, one of which is shown at 25, incorporating leak-oft nozzles 25athrough which, during operation of the coupling, working liquid flowsfrom the working chamber to the reservoir 18, where it is picked up bythe scoop tube, circulated through an oil cooler, and transferred backto the working circuit.

With the arrangement described, part of the overhanging weight of theprimary member 2 and part weight of the secondary member 1 is taken bythe stationary bracket 17a, which is set in true lateral alignment witheffective bearing 16 of the sleeve member 13 to be very slightly higherthan the centre line of the crankshaft of the engine.

In this manner the properties of the Weight of the primary and secondarymembers carried by the bearing 16 can be adjusted to reduce thecrankshaft deflection to an acceptably low figure.

Under the foregoing operating conditions the axis of rotation of theprimary members cannot be coincident with the axis of rotation of thesecondary members, and hence an adequate running clearance must beprovided around the output shaft 9, the said clearance measured radiallyWithin the sleeve member 15 being not less than $3 of the diameter ofthe output shaft 9 in the region where the greatest running clearance isrequired around said shaft.

In order to restrain passage of liquid from within the working chamberof the turbo coupling through the clear ance space 9a around the outputshaft 9, particularly under conditions of internal pressure resultingfrom high torque and slip and also from rapid transfer of liquid intosaid working chamber, an annular chamber 26 adjacent the output shaft 9is formed by the provision of a cylindrical member 27 one end of whichis fixed to the wall of the impeller boss 13, this member 27 beingconcentric with and spaced radially from the output shaft and projectingpartly over the flange 8 of the output shaft 9 into a recess 28 formedin the boss 7 of the runner 1. There is thus provided a labyrinth thatrestricts the entry of working liquid under local pressure into thechamber 26. To restrict the passage of liquid out of the chamber 26there is provided a second labyrinth seal in the form of an annularmember 29 of L-section bolted to the runner boss 7 with a cylindricalportion extending parallel to the runner shaft and projecting into anannular groove 30 in the impeller boss, being spaced radially within thecylindrical member 27. There is thus formed a second labyrinth thepurpose of which is to trap Within the chamber 26 liquid that has passedthe first-described labyrinth. A plurality of radially extending tubes31 are provided, spaced regularly around the axis of the coupling, eachtube 31 (only one of which is shown) communicating at its radially innerend with the interior of the chamber 26, and the radially outer end ofeach tube 31 projecting through the impeller shell and flange and sobeing in open communication with the reservoir 18. With thisarrangement, working liquid that is trapped in the chamber 26 isexpelled therefrom and directed into the reservoir 18 under the actionof the centrifugal pressure exerted on liquid in the tubes 31 when theimpeller 2 is rotating. A further drain to return to the reservoir anyliquid passing through the clearance space around the output shaft 9 maybe provided in the sleeve member at 15b near the outer end of the saidshaft; and a further labyrinth seal 32 may be arranged at the outer endof the 4 a shaft 9 within the stationary mounting 17 to direct anyliquid reaching that point into a drain duct 33 leading to a sump tank34 supporting the said bracket 17. The sump tank 34 may be arranged tobe continuously evacuated, when the coupling is running, by an ejectoroperated by the pressure created in the scoop tube and discharging backinto the reservoir 18.

In accordance with a further aspect of the present in vention there istherefore provided a hydraulic turbo coupling having vaned impeller andrunner elements, one of the said elements being provided with a shaftthat passes with a working clearance through a sleeve member connectedfor rotation with the other element and supported by a fixed externalbearing, and wherein there is provided an intercepting chamber with atleast one seal that restricts the flow of liquid therethrough situatedbetween the working chamber and the clearance space between said shaftand sleeve member, the said intercepting chamber being provided with atleast one duct through which liquid is ejected with the aid ofcentrifugal force when the turbo coupling is in operation. The said ductmay for example extend from said chamber to the outer profile diameterof the working circuit, or beyond.

An additional step that may be employed to restrain the leakage ofworking fluid along the clearance space is to taper the bore of thesleeve member 15 as shown, the bore being widest at the end adjacent theimpeller 2 so that when the coupling is running centrifugal force tendsto prevent Liquid from flowing to the outer end of the sleeve member 15.In this case the output shaft 9 is preferably also correspondinglytapered, as shown.

Evidently the present invention is not limited to hydraulic turbocouplings of the scoop control type provided with leak-off nozzles,e.g., couplings of the kind illustrated in British patent specificationNo. 493,703, in which the more the scoop tube orifice is extended themore liquid is transferred from the reservoir chamber to the workingcircuit. It can also be applied to couplings of the scoop trimming typeprovided with a filling pump or other source of pressure, and in whichthere is substantially free communication between the working circuitand a scoop tube chamber, so that increased extension of the scoop tubeorifice results in a reduced filling of the working circuit; see forexample British patent specification No. 719,470. The invention mayfurther be applied to turbo couplings in which a fixed scoop tube isprovided for transferring liquid from the working chamber through anexternal cooler and thence back to the Working chamber, see for example,British patent specification No. 328,028. The invention may be yetfurther applied to turbo couplings in which means other than a scooptube are employed for varying the filling of the working circuit, e.g.,a Vulcan hydraulic coupling with a pump; see, for example, Britishpatent specification No. 230,412.

In the above-described specific embodiment of the invention it isenvisaged that the sump tank 34 that supports the scoop tube manifold 17(which in turn supports the bearing 16 for the sleeve member 15 of theimpeller) will be of rigid construction and will be mounted on the sameheavy seating as the engine, so that the requisite conditions ofalignment can be maintained. In a modification of this arrangement themanifold 17 and bearing 16 may be supported by a rigid structure, e.g.,a bell housing solidly bolted to the prime mover and thus independent ofthe engine seating.

The prime mover will generally be a diesel engine to the crankshaft ofwhich the turbo coupling is rigidly connected as described above, butevidently a turbo coupling according to the invention may be used with adiesel englue or other engine or other types of 'prime movers, withappropriate modification if necessary of the connection of the part ofthe coupling that is driven by the prime mover. For example, an engineor an electric motor having an adequately stiff driving shaft may beconnected to the coupling through the medium of a diaphragm drivingplate, as is standard practice with electric motor drives to turbocouplings of the above-mentioned scoop control type. In the upper halfof the figure the coupling is shown as provided with such a drivingplate 34.

I claim:

1. A hydraulic turbo coupling comprising a primary part including avaned impeller and a secondary part including a vaned runner, saidprimary part also including a casing rotatable with said impeller andextending over the back of said runner and having a central hub, saidimpeller and said casing together forming a substantially closed workingchamber, and said impeller and said runner together defining a toroidalworking circuit wherein in the normal operation of the coupling arotating vortex ring of working liquid is established, a sleeve fastwith said impeller and projecting therefrom away from said workingcircuit, an output shaft fast with said runner and projecting throughsaid impeller and projecting also through said sleeve with a radialclearance, a bearing for said shaft within the hub of said casing, saidbearing being of a type that permits relative angular movement of theaxes of said impeller and runner by virtue of said radial clearance, abearing for said sleeve at the end thereof remote from said impeller, anadjustable stationary support for said last mentioned bearing, andtorsionally rigid means for drivably connecting the output element of aprime mover to said casing.

2. A hydraulic turbo coupling comprising a primary part including avaned impeller and a secondary part including a vaned runner saidprimary part also including a casing rotatable with said impeller andextending over the back of said runner and having a central hub, saidimpeller and casing together forming a substantially closed workingchamber, and said impeller and said runner together defining a toroidalworking circuit wherein in the normal operation of the coupling arotating vortex ring of working liquid is established, a sleeve fastwith said impeller and projecting therefrom away from said workingcircuit, an output shaft fast with said runner and projecting throughsaid impeller and projecting also through said sleeve with a radialclearance, a bearing for said shaft within the hub of said casing, saidbearing being of a type that permits relative angular movement of theaxes of said impeller and runner by virtue of said radial clearance, abearing for said sleeve at the end thereof remote from said impeller, anadjustable stationary support for said last-mentioned bearing, saidprimary part also including a reservoir rotatable with said impeller,and means for rigidly and drivably connecting the output element of aprime mover to said casing.

3. A hydraulic turbo coupling according to claim 2, including meanswhereby in the operation of the coupling working liquid flowscontinuously from said working chamber to an external circuit includingsaid reservoir and further means for continuously returning liquid fromsaid external circuit to said working chamber via at least one port inthe shell of said impeller.

4. A hydraulic turbo coupling comprising a primary part including avaned impeller and a secondary part including a vaned runner positionedrelative to said impeller to provide an annular space between them, saidprimary part also including a casing rotatable with said impeller andextending over the back of said runner and having a central hub, saidimpeller and said casing together forming a substantially closed workingchamber, and said impeller and said runner together defining a toroidalworking circuit wherein in the normal operation of the coupling arotating vortex ring of working liquid is established, a sleeve fastwith said impeller and projecting therefrom away from said Workingcircuit, an output shaft fast with said runner and projecting throughsaid impeller and projecting also through said sleeve with a radialclearance, a bearing for said shaft within the hub of said casing, saidbearing being of a type that permits relative angular movement of theaxes of said impeller for said sleeve at the end thereof remote fromsaid impeller, an adjustable stationary support for said last-mentionedbearing, and means for rigidly and drivably connecting the outputelement of a prime mover to said casing, means defining a liquidintercepting chamber between said working circuit and said clearancespace, said intercepting chamber having restricted communication at theinner profile diameter of said working circuit with said annular space,and at least one duct rotatable with said impeller and communicatingwith said intercepting chamber, and serving to eject liquid from saidintercepting chamber with the aid of centrifugal force when saidimpeller is rotating.

5. A hydraulic turbo coupling comprising a primary part including avaned impeller and a secondary part including a vaned runner positionedrelative to said impeller to provide an annular space between them, saidprimary part including a casing rotatable with said impeller andextending over the back of said runner and having a central hub, saidimpeller and said casing together forming a substantially closed workingchamber, and said impeller and said runner together defining a toroidalworking circuit wherein in the normal operation of the coupling arotating vortex ring of working liquid is established, a sleeve fastwith said impeller and projecting therefrom away from said workingcircuit, an output shaft fast with said runner and projecting throughsaid impeller and projecting also through said sleeve with a radialclearance, a bearing for said shaft within the hub of said casing, saidbearing being of a type that permits relative angular movement of theaxes of said impeller and runner by virtue of said radial clearance, abearing for said sleeve at the end thereof remote from said impeller, anadjustable stationary support for said last-mentioned bearing, saidprimary part also including a reservoir rotatable with said impeller,and means for rigidly and drivably connecting the output element of aprime mover to said casing, means defining a liquid intercepting chamberbetween said working circuit and said clearance space, said interceptingchamber having restricted communication at the inner profile diameter ofsaid working circuit with said annular space, andat least one ductrotatable with said impeller and communicating with said interceptingchamber, and serving to eject liquid from said intercepting chamber tosaid reservoir with the aid of centrifugal force when said impeller isrotating.

6. A hydraulic turbo coupling comprising a primary part including avaned impeller and a secondary part including -a vaned runner, saidprimary part also including a casing rotatable with said impeller andextending over the back of said runner and haw'ng a central hub, saidimpeller and said casing together forming a substantially closed workingchamber, and said impeller and said runner together defining a toroidalworking circuit wherein in the normal operation of the coupling arotating vortex ring of working liquid is established, a sleeve fastwith said impeller and projecting therefrom away from said workingcircuit,- an output shaft fast with said runner and projecting throughsaid impeller and projecting also through said sleeve with a radialclearance, a bearing for said shaft within the hub of said casing, saidbearing being of a type that permits relaitve angular movement of theaxes of said impeller and runner by virtue of said radial clearance, abearing for said sleeve at the end there of remote from said impeller,an adjustable stationary support for said last-mentioned bearing, andmeans for rigidly and drivably connecting the output element of a primemover to said casing, said radial clearance being not less than of thediameter of said output shaft measured in the region Where the greatestclearance is required around said output shaft to permit of relativeangular adjustment of the axes of said impeller and runner.

7. A hydraulic turbo coupling comprising a primary and runner by virtueof said radial clearance, a bearing part including a vaned impeller anda secondary part including a vaned runner, said primary part alsoincluding a casing rotatable with said impeller and extending over theback of said runner and having a central hub, said impeller and saidcasing together forming a substantially closed Working chamber, and saidimpeller and said runner together defining a toroidal working circuitwherein in the normal operation of the coupling a rotating vortex ringof Working liquid is established, a sleeve fast With said impeller andprojecting therefrom away from said working circuit, an output shaftfast with said runner and projecting through said impeller andprojecting also through said sleeve with a radial clearance, a bearingfor said shaft Within the hub of said casing, said bearing being of atype that permits relative angular movement of the axes of said impellerand runner by virtue of said radial clearance, a bearing for said sleeveat the end thereof remote from said impeller, an adjustable stationarysupport forsaid last-mentioned bearing, said primary part also includinga reservoir rotatable with said impeller, and means for rigidly anddrivably connecting the output element of a prime mover to said casing,said radial clearance being not less than of the diameter of said outputshaft measured in the region where the greatest clearance is requiredaround said output shaft to permit of relative angular adjustment of theaxes of said impeller and runner.

References Cited in the file of this patent UNITED STATES PATENTS2,187,667 Sinclair et a1. Jan. 16, 1940 2,212,901 Schneider Aug. 27,1940 2,264,340 Sinclair Dec. 2, 1941 2,271,919 Jandasek Feb. 3, 19422,281,161 Kuhns et a1 Apr. 28, 1942 2,379,015 Lysholm June 26, 19452,649,689 Oding Aug. Q5, 1953 2,784,555 Anderson Mar. 12, 1957

